In-situ doping of a conductive hydrogel with low protein absorption and bacterial adhesion for electrical stimulation of chronic wounds

2019 ◽  
Vol 89 ◽  
pp. 217-226 ◽  
Author(s):  
Yuhui Lu ◽  
Yanan Wang ◽  
Jieyu Zhang ◽  
Xuefeng Hu ◽  
Zeyu Yang ◽  
...  
2002 ◽  
Vol 282 (4) ◽  
pp. H1278-H1287 ◽  
Author(s):  
Pedro Boscan ◽  
Julian F. R. Paton

We determined the activity of neurons within the nucleus of the solitary tract (NTS) after stimulation of the cornea and assessed whether this input affected the processing of baroreceptor and peripheral chemoreceptor inputs. In an in situ, unanesthetized decerebrate working heart-brain stem preparation of the rat, noxious mechanical or electrical stimulation was applied to the cornea, and extracellular single unit recordings were made from NTS neurons. Cornea nociceptor stimulation evoked bradycardia and an increase in the cycle length of the phrenic nerve discharge. Of 90 NTS neurons with ongoing activity, corneal stimulation excited 51 and depressed 39. There was a high degree of convergence to these NTS neurons from either baroreceptors or chemoreceptors. The excitatory synaptic response in 12 of 19 baroreceptive and 10 of 15 chemoreceptive neurons was attenuated significantly during concomitant electrical stimulation of the cornea. This inhibition was GABAA receptor mediated, being blocked by pressure ejection of bicuculline. Thus the NTS integrates information from corneal receptors, some of which converges onto neurons mediating reflexes from baroreceptors and chemoreceptors to inhibit these inputs.


1988 ◽  
Vol 66 (3) ◽  
pp. 380-384 ◽  
Author(s):  
Sylvain Foucart ◽  
Jacques de Champlain ◽  
Reginald Nadeau

In this study, the reversal of the potentiating effect of idazoxan, a selective α2-antagonist, on adrenal catecholamine release elicited by splanchnic nerve stimulation in anaesthetized and vagotomized dogs, was investigated with the use of oxymetazoline, a selective α2-agonist. Stimulation of the left splanchnic nerve (5.0-V pulses of 2 ms duration for 3 min at a frequency of 2 Hz) was applied before and 20 min after the i. v. injection of each drug. Blood samples were collected in the adrenal vein before and at the end of each stimulation. The results show that the release of catecholamines induced by electrical stimulation was potentiated by 50% after idazoxan injection (0.1 mg/kg). This enhanced response was significantly antagonized by the subsequent injection of oxymetazoline (2 μg/kg). The α2-modulating effect appears to be related to the amount of catecholamines released during the stimulation, since by subgrouping of the data on the basis of the degree of potentiation by idazoxan, it was observed that this drug was more efficient when catecholamine release was higher during control stimulation. In contrast, the reversing effect of oxymetazoline was found to be more pronounced when catecholamine release was lower. These results thus suggest that the sensitivity of the α2-adrenoceptor mechanism may depend upon the in situ concentration of adrenal catecholamine release during electrical stimulation and that the potentiating effect of α2-blockade can be reversed by activation of those receptors by a selective α2-agonist.


1972 ◽  
Vol 57 (3) ◽  
pp. 661-671
Author(s):  
NOZOMU HISANO ◽  
HIDEKI TATEDA ◽  
MASUTARO KUWABARA

1. The distribution of the axons of the photo-excitative neurones in Onchidium verruculatum has been traced by intracellular stimulation of the soma and extracellular stimulation of the axon. They send axon branches mainly into the pleuroparietal and abdominal nerves in both sides. 2. In the whole-animal preparation, photo-excitative spikes could be recorded from neither the soma nor the nerves of inherently photo-excitative neurones during light stimulation. ‘On’ and ‘off’ spikes were initiated only immediately after the beginning and the cessation of illumination of a whole animal. 3. ‘Off’ spikes originated from dorsal eyes and stalk eyes to which shadow stimuli were applied. Those spikes were not the direct response of photo-excitative neurones to light. 4. The excitation of the inherently photo-excitative neurones in situ was suppressed by inhibitory inputs coming through the right and left pleuro-parietal nerves. Cutting one (or some) of the pleuro-parietal nerves was the only condition that diminished the inhibitory inputs to the photo-excitative neurones in the present work. Adequate electrical stimulation of the pleuro-parietal nerves inhibited spikes of photo-excitative neurones due to photo-excitator or spontaneous discharge.


2021 ◽  
Vol 9 (38) ◽  
pp. 8138-8146
Author(s):  
Ye Wu ◽  
Yuhui Lu ◽  
Can Wu ◽  
Jiali Chen ◽  
Ning Ning ◽  
...  

Polyaniline provides skin-mimic electrical conductivity and functionalized quaternary ammonium groups show intense antimicrobial activity. Electrical stimulation using conductive hydrogels shows great promise for chronic wound treatment.


1952 ◽  
Vol 98 (411) ◽  
pp. 265-272 ◽  
Author(s):  
H. McIlwain ◽  
P. J. W. Ayres ◽  
Olga Forda

Electrical stimulation of different areas of the human brain has hitherto been confined to experiments with the brain in situ, in living subjects. It has been carried out while the brain received its blood supply from normal sources. By chemical analysis of the arterial and venous blood and measurement of its rate of flow, information has been obtained on how metabolic changes in the brain vary with changes in its activity. However, these conditions can give information only about gross biochemical changes associated with stimulation; they are cumbersome, and would not indicate abnormal reactions in small areas. Also, they detect differences only in substances which are actively exchanged with the blood stream.


1983 ◽  
Vol 54 (6) ◽  
pp. 1558-1566 ◽  
Author(s):  
J. K. Brown ◽  
R. Shields ◽  
C. Jones ◽  
W. M. Gold

Discrepancies exist between reported effects of histamine on the alpha-adrenergic responsiveness of the canine trachealis muscle. Therefore, using an in situ preparation described recently (J. Appl. Physiol.: Respirat. Environ. Exercise Physiol. 49: 84–94, 1980), we tested the effects of histamine and other agents on alpha-adrenergic responses in the trachealis muscle of 34 anesthetized dogs. Under basal conditions, maximum alpha-adrenergic responses were small [3 +/- 1 (SE) g/cm] compared with those induced by a supramaximal parasympathetic stimulus (45 +/- 3 g/cm). After exposure of the muscle to histamine, responsiveness increased markedly to alpha-adrenergic stimuli, which included tracheal arterial injections of norepinephrine and phenylephrine or electrical stimulation of sympathetic nerves. Augmented alpha-adrenergic responsiveness persisted for 20 min after the end of contractions induced by histamine. Serotonin and long-acting, but not short-acting, cholinergic agonists also potentiated alpha-adrenergic responsiveness. We concluded that exposure of the trachealis muscle in living dogs to a variety of constrictor stimuli potently augmented its alpha-adrenergic responsiveness.


1972 ◽  
Vol 50 (6) ◽  
pp. 471-475 ◽  
Author(s):  
C. K. Chapler

The effect of intravenous administration of propranolol and/or epinephrine on glycogen stores in the dog gastrocnemius-plantaris muscle group was assessed at rest and following 30 min of contractions. In resting muscle, glycogen stores were not altered 60 min following propranolol (0.5 mg/kg) nor did a 10 min infusion of epinephrine (1 μg/kg/min) induce glycogenolysis. Following 30 min of contractions at 5 twitches/s, about 30% of the muscle glycogen stores were depleted. This rate of glycogenolysis was unaffected by prior administration of propranolol, suggesting that the breakdown of glycogen during electrical stimulation of the muscle group is not mediated through activation of beta receptors. When epinephrine was infused during the last 10 min of the contraction period, about 50% of the initial glycogen stores was depleted. This epinephrine-induced glycogenolysis was mediated through activation of beta receptors as it was abolished by pretreatment of the animals with propranolol. These data suggest that the relatively small breakdown of glycogen stores in the gastrocnemius-plantaris during electrical stimulation of the muscle group may reflect the lack of an increase in circulating catecholamines.


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